Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISA

Mycotoxins are the secondary toxic metabolites produced naturally by fungi. Analysis of mycotoxins is essential to minimize the consumption of contaminated food and feed. In this present work, an ultrasensitive electrochemical immunosensor for the detection of aflatoxin B1 (AFB1) was successfully de...

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Main Authors: Farah Asilah Azri, Rashidah Sukor, Jinap Selamat, Fatimah Abu Bakar, Nor Azah Yusof, Reza Hajian
Format: Article
Language:English
Published: MDPI AG 2018-05-01
Series:Toxins
Subjects:
Online Access:http://www.mdpi.com/2072-6651/10/5/196
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author Farah Asilah Azri
Rashidah Sukor
Jinap Selamat
Fatimah Abu Bakar
Nor Azah Yusof
Reza Hajian
author_facet Farah Asilah Azri
Rashidah Sukor
Jinap Selamat
Fatimah Abu Bakar
Nor Azah Yusof
Reza Hajian
author_sort Farah Asilah Azri
collection DOAJ
description Mycotoxins are the secondary toxic metabolites produced naturally by fungi. Analysis of mycotoxins is essential to minimize the consumption of contaminated food and feed. In this present work, an ultrasensitive electrochemical immunosensor for the detection of aflatoxin B1 (AFB1) was successfully developed based on an indirect competitive enzyme-linked immunosorbent assay (ELISA). Various parameters of ELISA, including antigen–antibody concentration, blocking agents, incubation time, temperature and pH of reagents, were first optimized in a 96-well microtiter plate to study the antigen–antibody interaction and optimize the optimum parameters of the assay. The optimized assay was transferred onto the multi-walled carbon nanotubes/chitosan/screen-printed carbon electrode (MWCNTs/CS/SPCE) by covalent attachment with the aid of 1-Ethyl-3-(3-dimetylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Competition occurred between aflatoxin B1-bovine serum albumin (AFB1–BSA) and free AFB1 (in peanut sample and standard) for the binding site of a fixed amount of anti-AFB1 antibody. Differential pulse voltammetry (DPV) analysis was used for the detection based on the reduction peak of TMB(ox). The developed immunosensor showed a linear range of 0.0001 to 10 ng/mL with detection limit of 0.3 pg/mL. AFB1 analysis in spiked peanut samples resulted in recoveries between 80% and 127%. The precision of the developed immunosensor was evaluated by RSD values (n = 5) as 4.78% and 2.71% for reproducibility and repeatability, respectively.
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spelling doaj.art-98a7de2c35dd4f91a7b231135b047ebb2022-12-22T03:59:36ZengMDPI AGToxins2072-66512018-05-0110519610.3390/toxins10050196toxins10050196Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISAFarah Asilah Azri0Rashidah Sukor1Jinap Selamat2Fatimah Abu Bakar3Nor Azah Yusof4Reza Hajian5Laboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, MalaysiaLaboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, MalaysiaLaboratory of Food Safety and Food Integrity, Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 Serdang, Selangor, MalaysiaDepartment of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor, MalaysiaDepartment of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor, MalaysiaFunctional Devices Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia, 43400 Serdang Selangor, MalaysiaMycotoxins are the secondary toxic metabolites produced naturally by fungi. Analysis of mycotoxins is essential to minimize the consumption of contaminated food and feed. In this present work, an ultrasensitive electrochemical immunosensor for the detection of aflatoxin B1 (AFB1) was successfully developed based on an indirect competitive enzyme-linked immunosorbent assay (ELISA). Various parameters of ELISA, including antigen–antibody concentration, blocking agents, incubation time, temperature and pH of reagents, were first optimized in a 96-well microtiter plate to study the antigen–antibody interaction and optimize the optimum parameters of the assay. The optimized assay was transferred onto the multi-walled carbon nanotubes/chitosan/screen-printed carbon electrode (MWCNTs/CS/SPCE) by covalent attachment with the aid of 1-Ethyl-3-(3-dimetylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Competition occurred between aflatoxin B1-bovine serum albumin (AFB1–BSA) and free AFB1 (in peanut sample and standard) for the binding site of a fixed amount of anti-AFB1 antibody. Differential pulse voltammetry (DPV) analysis was used for the detection based on the reduction peak of TMB(ox). The developed immunosensor showed a linear range of 0.0001 to 10 ng/mL with detection limit of 0.3 pg/mL. AFB1 analysis in spiked peanut samples resulted in recoveries between 80% and 127%. The precision of the developed immunosensor was evaluated by RSD values (n = 5) as 4.78% and 2.71% for reproducibility and repeatability, respectively.http://www.mdpi.com/2072-6651/10/5/196indirect competitive ELISAelectrochemical immunosensoraflatoxin B1multi-walled carbon nanotubeschitosanscreen-printed carbon electrodepeanut
spellingShingle Farah Asilah Azri
Rashidah Sukor
Jinap Selamat
Fatimah Abu Bakar
Nor Azah Yusof
Reza Hajian
Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISA
Toxins
indirect competitive ELISA
electrochemical immunosensor
aflatoxin B1
multi-walled carbon nanotubes
chitosan
screen-printed carbon electrode
peanut
title Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISA
title_full Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISA
title_fullStr Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISA
title_full_unstemmed Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISA
title_short Electrochemical Immunosensor for Detection of Aflatoxin B1 Based on Indirect Competitive ELISA
title_sort electrochemical immunosensor for detection of aflatoxin b1 based on indirect competitive elisa
topic indirect competitive ELISA
electrochemical immunosensor
aflatoxin B1
multi-walled carbon nanotubes
chitosan
screen-printed carbon electrode
peanut
url http://www.mdpi.com/2072-6651/10/5/196
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AT rashidahsukor electrochemicalimmunosensorfordetectionofaflatoxinb1basedonindirectcompetitiveelisa
AT jinapselamat electrochemicalimmunosensorfordetectionofaflatoxinb1basedonindirectcompetitiveelisa
AT fatimahabubakar electrochemicalimmunosensorfordetectionofaflatoxinb1basedonindirectcompetitiveelisa
AT norazahyusof electrochemicalimmunosensorfordetectionofaflatoxinb1basedonindirectcompetitiveelisa
AT rezahajian electrochemicalimmunosensorfordetectionofaflatoxinb1basedonindirectcompetitiveelisa